Fixed-knife drawer for planing machines



Feb. 19, 1929.

J. A. JoHNsoN FIXED KNIFE DRAWER FOR PLANIG' MACHINES Filed Junego. 1'927 PEF-J. Fir/55H Patented Feb. 19, 1929.

1,703,007- uni-ran STATES@ PATENT: orrlcr;.-

CARL' JOHAN AXEL Jonrrson,y orsf'rocxnomvr, swnnnn, Assxenon Toa; sa c. G.

BOLINDERS. MEKANISKA V'ERxsTnDs AKTIEB'OLAG', oF' STOCKHOLM; SWEDEN., A

CORPORATION.

FIXED-KNIFE DRAWER 'FOR' PLANING MACHINES.

Applicationmediana-2e, 1927., ser-mino. 290,210, and in sweden Mmmm; ,1927.

The present invention refersto. an arrange cuttings of a greater or smaller thickness.

Hitherto, the adjustment generally yhas been effected `,by'impartingblows to the knife :at rear edge, that is toI say at the; edge opposite to the cuttingA edge, so that the knife would be moved.inr.its'own plane andalongl its support.. This methodof procedure'1 has required greaty skilly and practice, particu# larly as the adjustments: arefor'such small measures as..0,03` to 0,2 millimeters. Great importance is` also. .tobe attached .to the euttingedge ofk the vknife.eide/nding.1in parallel to the working'plane after. the` adjustment: By reason.y ofrthe-.sinallv-measures of adjustf ment .it is not .pp ssibletoacontrol by measurementthat an adjustmentcarried out in this manner will be accurate. Therefore, the ricon-z trol-has been .entirely dependention the skill andthe practice of the,maehinistinhis.deterA mining by feelingwhether the c uttingswvonld be of .thefproper and uniform. thickness.

In orderx to obviate, thisdisadvantage,

amongothenste'ps the. arrangement lof providingfscrewsv beside thefrearyedge of the knife has been-.resorted to, saidfserewsbeing intended to bringabout a more uniform vdisplacementof the'knife inv its own planethan is possible to veffectbyanere blows. End'eav 'ours have also been ln-adeto so arrangethat part of. the.working` lplane ofthe drawer which is situated in` front of theknife, that the same would permit. of :being ,Y raised. and lowered.k Thesel arrangements, however, have not become satisfactory. i f OnY the other handthel arrangementfaimed at with the present. invention has been found to ifulfill .its purpose in .alldesired respects, and notonly can thewadjustment be; effected with .thegreatest accuracy and'wit-h measurable exacti'iess,.but it'canl also .beicarried v.out without .too .great an amount ofpraeticev or skill. y

r he-arrangement Y isprincipa;lly character.- ized by. the provision of; a knife ,holder for the'plaing knife, .which holder isA movable and guided inthewdrawer infsuch amanner that, .when theknifeholder is displaced in; the' drawer, the cutting'fedge of the knife is raised or lowered relatively to thatportion of the drawer in front of the knife which Coineides with the working. plane.

The arrangement is preferably devised zin such mannerthat the'knife holder is adapted vto be displaced to and fro in the longitudinal direction. of` he cutting edge -of the knife along, a .gi-iidev which is not parallel to thel working plane of the. drawenso that; the

holder is raised and lowered,A teget-hier with the knife, with respect to the Y workingplane, on displacement of the knife holder.

Instead, the' knife holdermay be rotatable inthe drawer, the axis of .rotation.entendi-ng,y parallel to thecutting edge. of.; the knife, which will thus be raised or lowered when the knife holder: is turned. The rotary move-y mentmayzbe brought about bythe provisionof a thread orlhejlicalslotin the' holder, said slot or thread haring agreat pitch, astudzor thelikefxed in .the'drawerbeifng adapted. to engage said-thread lorgslot.. Whenthek'nite holder is displaced in ,the longitudinal direction, itis turnedat thefsanietine through the action ofthe stud inthehelical slot.y

The accompanying drawings i'llustratetiio embodiments.oftheinvention.

' l is an elevation. of a;l iife-.,drawer.devised according to theinventiom the knife holder being displaceable to and froin the drawer. f

Fig.` Q shoxV Ysthe same knife.` drawerfviewe'd from above. Fi 3 shows the same knife drawer in cross section. i

. Fig.V 4. also shows across section: of vtheknife .drawer inserted in its place in the planing' machlne Fig. G'shows the/sam'e-knife drai'verviewed from above..

Fig. 7 shows across section; of the' knife vdrawer accordingtolligs. .5 andltl 1 designates the part formingl the knife drawer, said partbeing, adapted to be' los'ely vinsertedfinlo apocket shaped in ageorrespondling inannerand .provided in the; fraineof the maehine, as shown in Eig.y et, said pocket belng provided with guideraijls Zadapted to support.thedrawen. According-to Fig.- 4, a l

plurality of drawers may be inserted in this manner adjacentone another. 3 denotes a work piece actuated by pressure rollers l. 5 is the knife holder adapted to be 'displaced to and fro in the knife drawer l, said knife holder having a. lil-shaped cross section, as shown in Figs. 3 and il, enclosing a correspondingly shaped part of the drawer, said latter part with its sliding surfaces 6 and 7 forming an oblique angle with the working plane 8 of the drawer, as illustrated in 1. Mounted in the one head piece of the drawer the screw 9, which is adapted with its inner threaded end to be screwed in the knife holder 5, said screw serving for displacement of the knife holder.

According to lfig. 3, the planer knife 19 proper consists of a thin lamina of a small width, said lamina. bearing rigidly against a. support in the knife holder where it is retained by the break iron 11 adapted to be fixed by a. nut 12 threaded onto a lined. screw 13 attached in the knife holder 5 and extending through the break iron 11. For the displacement of the break iron 11 relatively to the knife 10, there is provided according to Fig. 3 one or merescrews 14 at the rear edge Cil ofthe break iron, said screws being adapted to be screwed in the break iron and to be turned in the knife holder 5 by means of flanges 15 engaging the knife holder through a rotary movement. In adjusting the break iron, the nut 13 is loosened and the screws 11i are turned, whereupon the vnut is tightened up. The knife 10 may be adj usted per se, that is to say independently of the break iron, in that it bears against special screws 16 adapted to be screwed in members 17 sunk into the knife holder 5.

rlhus, raising and lowering of the cutting edge of the knife relatively to lthe working plane is effected simply by turning the screw 9.

As the knife l() per se need never` be directly af-,tuated by blows or in a similar way, the knife .need not, as is otherwise necessary', project outside its attachment. Therefore, it will be possible to make the knives proper in the simple manner disclosed in the drawing, that is to say so that each knife only forms a thin lamina of inconsiderable width. Thus the knife only requires a width of 12 millimeters, in distinction from previously used knives which have to be atleast 100 millimeters wide. Therefore, the knives according to the invention may be manufactured very cheaply. Another advantage of great practical importance and connected with the nature of the knives is thatI planing knives of one and the same simple type may be used throughout the planing machine, i.. e. not only in the knife drawers, but also in rotating cutters belonging to the machine. This involves a considerable saving.

By the fact that the planing knife need never, pointed out hereinbefore, be actuated per se, a further conditionr of the greatest importance will be available for obtaining an entirely plane and smooth surface on the wood material planed.

llilhen the adjustment of the break iron effected to correspond to a fine cut, that is to say to thin shavings, in such a. manner that the outer edge of the break iron 'll is displaced outwards toward the cutting edge of the knife, the opening 18 between the break iron and the ad] acent part of the knife drawer 1 is reduced. Reduction of the opening 13 will thus take place in the saniedcgree as the shavings have to be thin. For coarser shavings, on the other hand. when the break iron 1.1 is removed with its edge from the cutting edge of the knife, the opening 18 will he larger, i. e. corresponding to the .coarser shavings. ln earlier arrangements where the knife and the break iron attached thereto are displaced in their own plane, the opening` will again be larger for thinshavi' gs and smaller for coarse shavings, which obviously an incorrect state of things.

ln the embodiment according to Figs. 5 to 7, the knife holder 5 is rotatable, as already pointed out hereinbefore, the axis of rotation extending in parallel to the cutting edO'e of the knife 10. The holder is steadily guided in that 'he cylindrical surface thereof is tightly enclosed by the drawer 1 which, correspondingly, is cylindrically shaped on its inside. Besides, the one end of the holder is formed into a pivot 19 mounted in the'one head piece of the drawer. Mounted in the opposite head piece is the screw 9 adapted to be screwed in the holder. This holder is provided with a longitudinal slot 20 having a great pitch, an abutment 21 provided on the inside of the drawer engaging into said slot.- l/Vhen the screw 9 is turned, the knife holder 5 is displaced in its longitudinal direction, the abutment 21 sliding in the slot 20 and exerting a turning action on the holder, so that the cutting edge of theknife 10 is raised or lowered relativelyto the working plane of the drawer.'

As already set forth hereinbefore, each knife drawer issituated obliqnelyV with ref spect to the feeding direction ofV the wood material., that is to say, in such a manner that the edges of the knife drawer and the corre` spending edges of the pocket, into which the drawer is inserted, forman oblique angle with the feeding direction. On account of this oblique position, the advantageous eondition is obtained, that the force which durwork acts upon the drawerl in the said direction will be divided in such a manner 1 that one of its l,components will powerfully counteract displacement ofthe dra-wer out of the pocket. If the obliquel position is suitably adapted, the said force will therefore, in connection with the friction between the CII different positions `that the boards may as@ suine during the feeding thereof. i

Ifilhcn the knife drawer is inserted in its pocket, it is displaeeable in the longitudinal direction of the cutting edge of the knife. This arrangement entails the Very important advantage that the drawer may be displaced, without altering the distance between the cutting edge and the pressure rollerssl shown in Fig. 4l. Thus, cooperation between the rollers and the Adrawer is maintained quite independently of the positions of displace nient occupied by the drawer. Consequently, if only a portion of the length of the cutting edge ofthe knife is utilized on a certain oc casion for the planing operation .and is thus worn', another portion of the edge, which is not worn, may come to use on some other occasion, simply by the. .drawer being displaced so that the unworn portion ofthe edge is brought into working position.

l. In a planing machine, a frame having a plane upper surface provided with an opening therein, guides on the underside ofthe n fi'an'ie below said opening, ardrawer supported on said guides below said opening having v its upper surface in the plane of said frame surface, aY knife holder supported by said drawer, a guide onl said drawer engaging said knife holder and extending obliquely `to the cutting edge of said knifeand tothe upper surface of said drawer, and means secured to said drawer and engaging said knife holder vto move the knife holder On said guide, .whereby the knife is moved upwardly -and forwardly through the opening in the frame member.

2. In a planing machine as claimed in `claim l in which. the knife adjusting means comprises a screw mounted in an end of the drawer and whicliengages an end of the knife holder to move the knife holder transversely of the drawer.

3. In a planing device as claimed in claim 1` in which the cutting edge of the cutting knife and the side of the'knife drawerwhich engages the guide and against which the force of the moving material forces the knife drawer are parallel to eachother and at an oblique angle to the direction of the moving material as and for the purposeset forth.V

In testimony whereof I aiiiX my signature.

CARL JOHAN AXEL JoiiNsoN. 

